6G15 stand alone reverb (PT and Reverb tranny qns)

[tubeswell]

In comtemplating whether to build a new amp with reverb and trem (which I still am thinking about), my mind then turned to wondering about the 6G15 (which I could simply hook up to my existing 5G9 - or whatever other tweed amp I want to build).

1) Reverb tranny qns
Hoffman site says you can use a 6V6 or a 6K6 to drive the reverb tranny.

http://www.el34world.com/Hoffman/images/fendrev.gif

Can I use a P-TF22921 tranny with a 6V6/6K6 driver? (or should that kind of tranny be kept for use with twin triode 12A_7 driver?)

http://www.tubesandmore.com/scripts/...item=P-TF22921

2) Power tranny qns
The fender scheme (see attachment) lists the PT as a 68319-A (for which tubesandmore.com offer a P-TF47609 - 340VDC@0.7mA , 6.5V@1A). I can't find any spec on the net through my searches for far for a 68319-A, so I trust the P-TF47609 spec is good.



Why is the PT HT flicked through 3 diodes off one side of the winding in the Fender Scheme? I suspect it is to rectify the HT (but if it is already a DC supply, what gives?) Or is it something to do with the relatively high HT winding voltage (i.e. for something that is only driving 1 x 6V6/6K6 and two 12AX7s)?

What sort of diodes are they? 1N4007?

[stokes]

The Fender schem uses a half wave rectifier.That transformer may work,but it isnt ideal.You want something with about 6 to 8k primary for a 6K6 or 6V6.Check www.tedweber.com the WRVBPT PT and the WO22905 for the driver.I've used them and they are good.

[quayhog]

Use Champ transformers and full wave rectify it. It'll work great.

[6267]

The lower power output transformer for the 12??7 triode reverb drivers are pretty minimal...mine blew on one amp and I replaced it with the output transformer from an AA5 radio. You might also consider ecl82, 6dn7 or another power tube/pre-amp tube combo envelope so that you can minimize chassis space. My amp drives the tank with one half a 12dw7 (essentially a 12au7 on the driver side) and it gets plenty reverby. You don't *need* to use a 5 watt output on the tank, but I understand the allure...some of the lower power 6v6 variants sound very different and very good as well.

[tubeswell]

Thanks for all the pointers you good people.

I've ordered a 15W champ SE OT with the intent of driving it with a 6V6. I haven't absolutely decided what to do about the PT yet.

I have a 2nd-hand PT that is 376VAC with no CT and might be okay with a 1/2-wave rectifier and a choke filter and I have a 90mA choke filter on order, but I'm tempted to keep that for a tweed pro/bandmaster/bassman, and maybe go with a FW diode-rectified (NOT Bridge Rectified) lower power PT that has a CT (and use an RC filter instead).

So I was reckonining I'd need about 340VDC on the Plate supply (so that's got to be a 240-0-240 secondary at about 100mA?) - would that feed too much current into the pan (Its an accutronics type 4)

[tubeswell]

Okay so I just saw the Tore T site, where he recommends using something in 220-240VAC winding range for the revibe , so I'll go with that.